【摘要】 目的：观察一次离心运动后不同恢复时程大鼠骨骼肌程序性坏死的趋势变化，分析RIPK1/RIPK3途径在运动性骨骼肌损伤及修复中的可能作用。方法：70只雄性8周龄Sprague-Dawley（SD）大鼠据体重随机分为安静对照组（C,n=10）和运动组（E,n=60），其中E组又根据不同时程分为运动后即刻、运动后12 h、24 h、48 h、72 h、120 h共6组，每组10只。E组大鼠持续性下坡跑（-16°，16 m/min,90 min）。各组分别于相应时程点对比目鱼肌进行取材。透射电镜观察比目鱼肌超微结构变化，蛋白质印迹检测比目鱼肌程序性坏死蛋白RIPK1、p-RIPK1^S166、RIPK3、p-RIPK3^S232、MLKL、p-MLKL^S358、HMGB1、IL-1α等表达。结果：1)一次离心运动后恢复期比目鱼肌超微结构发生改变，在恢复期12—48 h肌纤维排列紊乱，线粒体肿胀明显，肌膜下大量线粒体聚集；2)一次离心运动后恢复期比目鱼肌细胞膜形态改变，运动后48 h肌纤维细胞膜不完整、起皱受损明显，72 h与120 h逐渐恢复；3)MLKL表达在恢复期48 h达到峰值，在恢复期24 h（P<0.05）和48 h（P<0.01）明显升高；p-MLKL^S358表达在恢复期48 h达到峰值，在恢复期48 h（P<0.01）和72 h（P<0.01）显著升高；p-MLKL^S358/MLKL比值在恢复期72 h达到峰值，在恢复期12 h（P<0.05）和24 h（P<0.05）明显降低，72 h（P<0.05）显著升高；HMGB1表达在恢复期48 h达到峰值，在恢复期24 h（P<0.05）和48 h（P<0.01）显著升高；IL-1α表达在恢复期12 h达到峰值，在12 h（P<0.01）、24 h（P<0.05）和48 h（P<0.01）明显升高；4)RIPK1表达在恢复期48 h达到峰值，在恢复期运动后即刻（P<0.01）、12 h（P<0.01）、24 h（P<0.01）、48 h（P<0.01）、72 h（P<0.01）、120 h（P<0.01）均显著升高；RIPK3表达在恢复期48 h达到峰值，在恢复期48 h（P<0.01）、72 h（P<0.01）、120 h（P<0.01）明显升高；p-RIPK1^S166蛋白表达呈现先升高后降低的趋势，在恢复期72 h（P<0.01）显著升高；p-RIPK3^S232表达在恢复期72 h达到峰值，运动后即刻（P<0.05）和12 h（P<0.05）明显降低，72 h（P<0.05）显著升高。结论：1)一次离心运动后恢复期比目鱼肌发生程序性坏死现象，在运动后48 h相对明显；2)一次离心运动后恢复期比目鱼肌程序性坏死现象可能由RIPK1/RIPK3途径介导。更多还原

【Abstract】 Objective:To observe changes in the trend of necroptosis in rat skeletal muscle at dif‐ferent recovery time intervals after a single eccentric exercise and to analyze the possible role of the RIPK1/RIPK3 pathway in locomotor skeletal muscle damaged and repair.Methods:Seventy male 8-week-old Sprague-Dawley （SD） rats were randomly divided into a control group （C,n=10）and an exercise group （E,n=60） according to their body weight,of which group E was divided into six groups of 10 rats each according to the different time intervals of the six groups,includ‐ing immediately after exercise,12 h,24 h,48 h,72 h,and 120 h,and so on.Group E rats were subjected to continuous downhill running （-16°incline,16 m/min speed,90 min exercise time）.Each group takes soleus muscle samples at the corresponding time schedule.Transmission electron microscopy was used to observe the ultrastructural changes of rat soleus muscle,and Western blot was used to detect the expression of soleus muscle necrosis proteins,such as RIPK1,p-RIPK1^S166,RIPK3,p-RIPK3^S232,MLKL,p-MLKL^S358,HMGB1,IL-1α,etc.Results:1) Ultra‐structural changes in soleus muscle during the recovery period after a single eccentric exercise,with disturbed arrangement of muscle fibers,obvious swelling of mitochondria and a large num‐ber of mitochondrial aggregates under the muscle membrane from 12 h to 48 h during the recov‐ery period;2) morphological changes in the cell membrane of the soleus muscle during the re‐covery period after eccentric exercise,with an incomplete,wrinkled and damaged cell mem‐brane of the muscle fibers at 48 h,followed by a gradual recovery at 72 h and 120 h;3) MLKL expression peaked at 48 h during recovery,and significantly increased at 24 h （P<0.05） and 48 h（P<0.01） during recovery;p-MLKL^S358 expression peaked at 48 h during recovery,and was sig‐nificantly decreased at 48 h （P<0.01） and 72 h （P<0.01） during the recovery period;p-MLKL^S358/MLKL ratio peaked at 72 h during the recovery period,significantly decreased at12 h （P<0.05） and 24 h （P<0.05） and significantly increased at 72 h （P<0.05）;HMGB1 ex‐pression peaked at 48 h during the recovery period and significantly increased at 24 h （P<0.05）and 48 h （P<0.01） during the recovery period;IL-1α expression peaked at 12 h during the recovery period,significantly increased at 12 h （P<0.01） and significantly increased at 72 h （P<0.01）.peaked at 12 h,and significantly increased at 12 h （P<0.01）,24 h （P<0.05） and 48 h （P<0.01）;4) RIPK1 expression peaked at 48 h during the recovery period,and was significantly elevated at the immediate post-exercise （P<0.01）,12 h （P<0.01）,24 h （P<0.01）,48 h （P<0.01）,72 h（P<0.01）,and 120 h （P<0.01） during the recovery period;RIPK3 expression peaked at 48 h during the recovery period,and was significantly elevated at the recovery period 48 h （P<0.01）,72 h （P<0.01）,and 120 h （P<0.01） were significantly elevated;p-RIPK1^S166 protein ex‐pression showed a trend of increasing and then decreasing,and was significantly elevated at 72 h（P<0.01） during the recovery period;p-RIPK3^S232 expression peaked at 72 h during the recov‐ery period,and was significantly elevated at the immediate post-exercise period of the recovery period （P<0.05） and at significantly decreased at 12 h （P<0.05） and significantly increased at72 h （P<0.05）.Conclusions:1) The occurrence of necroptosis in the soleus muscle during the recovery period after a single eccentric exercise is relatively obvious at 48 h after exercise;2) the necroptosis in the soleus muscle during the recovery period after a single eccentric exer‐cise may be mediated by the RIPK1/RIPK3 pathway.更多还原